Embodiments of the invention relate generally to x-ray diffraction (XRD) systems and, more particularly, to an x-ray source and detector configuration in a non-translational XRD system.
In recent years, the detection of contraband, such as explosives, being transported in luggage and taken onto various means of transportation has become increasingly important. To meet the increased need for such detection, advanced Explosives Detection Systems (EDSs) have been developed that can not only detect suspicious articles being carried in the luggage but can also determine whether or not the articles contain explosive materials.
These detection systems, at a minimum, include computed tomography (CT) machines that are capable of acquiring mass and density information (as well as additional information, such as an effective atomic number) on items within luggage. To acquire more detailed and highly selective information on luggage being scanned, explosives detection devices based on x-ray diffraction (XRD) can be employed in combination with the CT system to provide complementary information relative to the data from the CT system, thereby improving the overall detection performance of the EDS. That is, the complementary information gained from the XRD system, when combined with the CT data, can provide higher detection sensitivity with reduced false alarms as compared to CT data alone, thus resulting in less manual or follow-on inspection needed to clear the alarms and preventing inspection system backup.
Commercial designs of XRD systems, however, limit the throughput achievable in existing EDSs that combine various scanning and detection technologies. That is, XRD systems presently in use typically emit a highly collimated X-ray beam that is small in diameter toward a region of interest (ROI) in an object to be interrogated. To investigate additional ROIs in the object, the object has to be repositioned and/or the x-ray source and detector combination has to be mechanically repositioned to illuminate the new ROI. This repositioning of either the object or of the collimator/detector arrangement in the system can lead to increased scanning time and greatly reduce baggage scanning rates.
Therefore, it would be desirable to design an apparatus and method for reducing the scanning time of objects in an XRD system. It would also be desirable to control the XRD system to interrogate ROIs in the object based on data acquired from a separate imaging system to further increase efficiency in operation of the XRD system.